DevTools: Fix JSDoc and code related to method overriding

R=yurys@chromium.org, vsevik, yurys

Review URL: https://codereview.chromium.org/761433002

git-svn-id: svn://svn.chromium.org/blink/trunk@185949 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[DevTools] Move from InspectorFrontendAPI to DevToolsAPI.

This also removes extra InspectorFrontendHost usages.

BUG=431697

Review URL: https://codereview.chromium.org/753243002

git-svn-id: svn://svn.chromium.org/blink/trunk@185952 bbb929c8-8fbe-4397-9dbb-9b2b20218538